Antiaircraft fire control table



April 9, 1935. Y. P. G. LE PRIEUR El AL ANTIAIRCRAFT FIRE CONTROL TABLE Filed Oct. 18,1933 6 Sheets-Sheet 1 Fig-I April 1935- Y. P. G. LE PRIEUR ET AL ANTIAIRCRAFT FIRE CONTROL TABLE Filed Oct. 18, 1933 6 Sheets-Sheet 2 April 9, 1935.

Y. P. (5. LE PRIE UR El AL ANTIAIRCRAFT FIRE CONTROL TABLE Filed 001:. 18, 1933 6 Sheets-Sheet 3 5 i ,EEEJ.

April 9, 1935. Y. P. GJLE PRIEUR ET AL 1,997,303

ANTIAIRCRAFT FIRE CONTROL TABLE Filed Oct. 18, 1933 6 Sheets-Sheet 5 April 9, 1935. Y. F 6.1.5 PRIEUR ET AL 1,997,303 ANTI AIRCRAFT FIRE CONTROL TABLE Filed Oct. 18,-1933 6 Sheets-Sheet 6 z/mfiw w VII Patented Apr. 9, 1935 I v UNITED STATES PATENT OFFICE ANTIAIRCRAFT FIRE CONTROL TABLE Yves Paul Gaston LePrieur and Auguste Louis Ricordel, Paris, France, assignors to Society la Precision Moderne, Paris, France, a corporation of France Application October 18, 1933, Serial No. 694,140 In France October 20, 1932 11 Claims. (01. 89- 4130) The present invention concerns a device proing and pitching motion. One is thus forced to viding. the possibility of transmitting at a dismake one part of the device, for instance the sight tance the indications concerning the position in glass, dependent on the movements of the ship, space of a 'portion of a straight line movable whilst the gun-parallel arm is made to depend around a fixed point, particularly applicable for on a plate which is constantly kept horizontal 5 firing upon movable objectives, the portion of a by means of a gyroscopic device for instance. It straight line being in this case the gun-parallel is obvious that the angles which are in this way arm of a directing device of any known type. transmitted by the device are thus precisely the Let 0 be a point fixed in space and around angles that have to be made by the guns with which the line 0A may turn (Figure 1). It is respect to the deck of the ship for attaining the in obvious that by means of the two planes V and H objective. passing through 0 the one vertical and the other By way of example, a preferred embodiment of horizontal, any position of the segment 0A may the invention will now be described with referbe defined by two angles, and this, in two ways ence tothe accompanying drawings, together with by using two different systems of coordinates. its application to anti-aircraft firing for land 15 The first way consists in using as coordinates: and marine guns.

'(a) The angle 1' between the intersection line Figure l is a diagram serving to illustrate the Or: of the two reference planes and the projecprinciple of the device. tion 0A of the line CA on the verticalplane V. Fi u e 2 is a p sp tiv v w f a fir This angle will be referred to in the following rector of a known type. V 20 as apparent inclination. Figure 3 is a diagram concerning a corrector of (b) The angle "d between the line 0A and its the type of Figure 2. projection DA on the vertical plane V. This Figure 4 is a perspective view of the whole of angle will be termed the true angle of drift. a director with direct aiming, object of the inven- The second way'consists in-using: tion, and comprising a corrector according to 25 (a) The angle I, true inclination, between gure r the line 0A and its projection DA" on the hori- Figure 5 is a perspective view of the whole of zontal plane H. g a director for a central station, also comprising (b) The angle do, horizontal drift" between a corrector after Figure 2.

0a: and the projection 0A" of CA on the hori- Figure 6 is a geometrical figure showing the 30 zontal plane H. correction angles used.

In the above, it has been assumed that thetwo Fi r 7 is a ver ical cti n hrou h th ereference planes V and H are fixed. In practice vice which is the obje f the invention. however, when it is desired to command the flr- Figure 8 is an elevational view of the angle ining upon a moving objective, the vertical plane dicators. containing the sighting telescope of the corrector Figures 9, 10 and 11 show details of construeis taken as vertical .reference plane, the line 0A tion of the device and the mann r of using the representing, as indicated above, the direction device in the case of indirect firing. of the gun-parallel arm. Thus, the reference Figure 12 concerns an electric servo-device for g y r plane V becomes movable, and in the case of the follow-up y m indirect firing corresponding to the second sys- Figure 13 shows in sectional elevation the moditem of coordinates, the guns are being transfieddevice for use in connection with guns on mitted not only the horizontal drift do, but also board of a ship. the bearing Zo of the plane of sight V (i. e. the In the description of the device which is the for detennining th horizontal pr j tion of 0A, tion with an anti-aircraft firing corrector of the In the case where the device is designed to type described in the prior U. S. Patent 1,844,429 control the firing of the. gun of a ship subject to f the inv n rs. The new director may of course 50 rolling. and pitching, the horizontal reference be e p oy in connection With any other known 50 plane H also becomes movable. In fact, it is firing correctordesired to transmit to the guns the angles deter- In order to render the present description more mined with respect to the deck of the ship on readily comprehensive, the principle and the opwhich they are fixed, the position of this deck eration of the corrector which has been chosen in space varying continuously owing to the rollfor the sake of example, will be briefly recalled. I

4.) angle between Orcand the north-south line), in Object the present invention, the latte! as order to obtain the angle Z which is indispensable been illustrated, by way of example, in connec- The corrector which is represented in perspective view on Figure 2 is designed to reproduce at a reduced scale the three-dimensional polygon of Figure 3, the four sides of the said polygon repre- 5 senting respectively the present distance OA0=D0 of the objective, the distance AoA1=Vt travelled through by the objective at the speed V during the time t of the travel of the projectile, the drop A1B=p of the trajectory of the projectile at the point where the projectile attains the objective, and the length OB=L along the tangent at the origin of the trajectory (i. e. along the produced axis of the gun) till to the vertical 1113:!) of the point where the projectile attains the objective. In the patent concerning this corrector, in which the sight-glass is moved with respect to the gun, the variable scale of reduction has been chosen equal to 1/L. This choice oflfers the advantage of giving a constant length to the side representing the axis of the gun. Then, as in the present case, it is desired to control a director whose sightglass is continuously directed towards the objective and in which the gun-parallel arm is displaced with respect to the sight-glass, it is preferable to choose the reduction scale also variable and equal to l/Do, said choice resulting in the advantage that the side representing the line Do is thus given a constant length, and that the pointer is not displaced during adjustment of the device. The rotation of a disc connected to certain appropriate transmission parts may deform this polygon so as to give its sides OB, AOAI and A13 of given direction (the last side Do parallel to the sight-glass being the fixed length if 1 taken as unity, according to the above) a series of successive values each of them corresponding to a determined firing at a given distance. This disc carries an abacus consisting in curves of equal distance Do traced in terms of D. in front of the abacus a pointer may move, the displacements of this pointer representing the variations of the length of the side L E whereby it is possible, by operating the instrument until the pointer comes upori the curve Do corresponding to the telemetric distance of the objective, to realize with the instrument the polygon exactly corresponding to the considered case offiring. A

The instrument, as it is shown by Figure 2, comprises a frame I, which is maintained vertical by means of aparallelogram and two arms, one of which 4 is of fixed length and is kept constantly parallel to the sight-glass I 5, whilst the other arm 8 is of the telescope type and-thus of variable length and remains constantly parallel to the gun. This arm of ,variable length is called the 1 gun-parallel arm of the corrector.

In order to simplify the description, only the correction terms AoA1=Vt of the displacement of the objective and the drop p of the trajectory have been taken into account. It is obvious that the director may just as well be'combined with a corrector of a similar but more elaborate type giving, further, the correction due to the wind and that due to the movement of the gun itself, the vector AoA1 representing in this case the resultant R of the three partial correctionvectors.

Figure 6 is a perspective diagram where the polygon OAoA1B of Figure 3 is recognized.

The plane Q is the vertical plane containing the present line of sight 0A0, axis of the sightglass.

The plane P is the horizontal plane passing through the observing station.

The point E is the projection of the point B' on the plane Q, the point C, that of the point B on the plane P, and F is the projection of C 0n the plane Q. In' the case of direct firing, the un receives:

(a) The angle s of total correction of the site, which is equal to SoI' (so is the present site and I the projection of the inclination I or the angle between the axis of the gun and the horizontal),

(b) .The leeway drift angle d in the plane passing through the axis of the gun and normal to the plane Q.

In the case of indirect firing, the angles to be transmitted to the guns are:'

(a) The inclination I of the gun,

(b) The azimuth Z of the gun, equal to the sum of the azimuth Zo of the sight-glass and of the projection dh of the angle d on the horizontal plane. The angle (in is the horizontal drift.

Figures '7 and 8 show the mechanism serving the purpose of measuring the angles s and d in the case of direct firing, and Figures 9, 10 and 11 show how the same mechanism is used for the purpose of measuring the angles I and Z in the case of indirect firing. v

The main rod 8, whose direction is substantially that of the gun glides inside a sleeve 19 whose axis passes through thecenter Ill. The sleeve 19 is pivoted on journals 80, in a frame 8| whose horizontal axis is on the same level as the cen-,

ter l8.

This frame is supported by journals 82 in a piece 83 formed as a fork and adapted to rotate round a vertical axis passing through thevpoint I8 by means of a toothed wheel 84. In the case of direct firing, this wheel does not turn and the axis of the journals 82 lies along the produced axis I. V

One of the journals of the support 83 is pro,- duced by a graduated limbus 85 in form of a quarter of a circle. A pointer 86' integral with the frame 8| moves in front of the limbus 85.

The sleeve 19 is provided with a conical sec- 'tion 81 engaging with a pinion 88 whoseaxis carries a pointer 89 moving in front of a divided circular-disc 98 integral with the frame 8|.

By referring to Figures 2 and 6, it may be easily seen that the pointer '86 indicates the value of the angle I and the pointer 88, that of the angle d.

A pointer 9|, integral with a toothed wheel 9| is used for following up the angle Iby simply bringing it into coincidenc with the pointer 86.

This following up is done by means of the wheel 92 (Figure 7) acting on one hand upon the worm drive 93 Figure 8, and on the other hand on a differential 94 which receives from the worm drive 95 a movement which is proportional to so.

The shaft 96 of the differential can transmit 1 to the guns the angle S0I'=8 necessary for direct firing.

This transmission may be done either directly by mechanical means; or electrically by meansof a transmitter 91 (Figures 7 and 8).

A crank 98 serves to record, by means of a worm drive 99, I80 (Figure 9) operating a pointer I01, the indications of the pointer 89 proportional 60 \tlon of the transmitted power.

to the drift d.

This element may also be transmitted either mechanically or electrically by means of a transmitter Hill.

In the case of indirect firing, the same device serves to determine the angle of pointing and the azimuth of the gun.

The angle I is automatically indicated by the operation of the drift indicator. The latter.instead of acting on the crank 98., turns the crank I93 (Figure 9) and turns the support 83 until the pointer 89, indicating the value of the angle d, is made to read zero on the dial 98 (Figure 8) At this moment, the horizontal axis of the frame 8| is perpendicular to the direction of the main rod 8 and the rotation of this'frame round its horizontal axis, indicated by the pointer 86, indicates the angle of themain rod with the horizontal, i. e. the inclination I ofthe gun.

The crank 92 serves to record this angle, but the differential 94 has to be disconnected or made inoperative by means 6f an appropriate clutch (Figure 7). I

The rotation round its vertical axis of the piece 83 is proportional to the horizontal drift dh- In fact, the wheel 84 has turned through the angle between the trace 06- of the vertical plane containing the present objective and the trace of the vertical plane containing the gun, i. e, the angle (in.

A differential I28 (Figure 11) is placed so as to totalize the rotation of the worm wheel operated by the wheel 14 of the deflection pointer, which turns proportionally to the angle. Z0 and the rotation of the worm wheel I84, which is proportional to the angle dh.

The shaft I (Figure 11) driving the transmitter Hi turns proportionally to the sum of these two angles, Zo+dh=Z.

In thecase of direct as well as in the case of indirect firing, the cranks 82. 98 and I88 may be replaced by a servo-mechanism, the movement of whichis controlled by a set of contacts placed on a part which is integral with the mechanical part whose position gives the element which is to be followed up (Figure 11) Thus, for the angle of firing I, the pointer 88 (Figure 8) carries a contact-spring I86 (Figure 12) movable between two studs l8! and I08, whose object is .to reverse the drive of the servo-mechanism. The inventors have already imagined before a servo-device of this sort with contact amplifiers, such a device being integrally applicable in the present case.

The use of servo-devices avoids the necessity of having a follow-up servant. It ensures an instantaneous following and enables amplifica- Figure 5 is a general representation of a director at the central station.

The site so is sent from an outer observatio station to an electric receiver I89 controlling the present site arm H8 placed inside a frame I parallel to the vertical plane of the present site.

This vertical plane is assumed to be fixed and 5 it is from the trace of this vertical plane, taken as origin, that all the angular azimuth and orientation indications concerning the objective, the wind and the movement of the gun itself are computed. These indications are represented by the dials H2, H3, I if placed in convenient directions.

The initial indication is at first set by hand on these dials, and a receiver H5 for the present azimuth so enables the indications to be constantly kept at the correct value with respect to the present site.

The axis of rotation H8 of the arm I I8 is fixed A mechanical assemblage comprising the parts measuring the corrections in the case of direct firing, and measuring the inclination and the future azimuth in the case of indirect firing, is.

carried on the end of the arm I I0.

A device, which is not shown, maintains the axis of the plate H8 vertical.

'I'he'following up operation is exactly the same as that in the director which has already been described.

The receiving and the transformation of the present distance are done in a block H9 placed on the side of the frame III.

In the case where the device is installed on board a ship, the angles which have to be transmitted to the guns are the apparent inclination and the apparent drift, the first of these indications being measured with respect to the deck of the ship, and the second with respect to'the guideline of the ship. But as the deck is not a fixed horizontal plane, owing to the rolling and pitching, it is necessary, in order that the apparent drift and the apparent inclination may correspond at any instant with the position of the objectiv'e, to introduce into the device an additional reference plane which remains horizontal notwithstanding the movements of the ship.

The fork 83 (Figure 7), in which the frame 82 may turn, is in this case no longer supported directly by the frame of the device, but by means of a'pair of circular sliding parts 358 and 859 (Figure 13) placed at right angles and provided with toothed sectors driven by two worm wheels 855 and 856 so that the plane of the disc 351 on which is placed the fork 83 may perform, with respect to the plane of sight which is .constantly perpendicular to the deck of the ship, movements which are exactly opposite to the movements of the deck with respect to an ideal vertical plane, fixed in space. To this effect, the sliding parts are placed in sucha manner that one of them 358 is constantly parallel to the guideline of the ship. This is obtained by giving the pivot 348 an angular displacement equal in value, but of opposed direction to the drift'of the objective, by means of the screw 360.

The sliding part 358 then receives on behalf of the gyroscope of the telepointer an angular displacement equal to the angle of pitch, and the sliding part 858, which is perpendicular to the first, is' given an angular displacement equal to the angle of roll.

The operation with respect to the plane of the disc 351 is the same as that indicated with respect to the horizontal plane in the case of land guns. The pointer 9| indicates the angle of apparent inclination, and the rotation of the crank I03 destraight line movable "around a fixed point, particularly designed to transmit to an antifaircraft dicular to the sight plane, the said finger indicates battery of guns or machine-guns the elements of direct and indirect firing obtained by means of an appropriate known corrector provided with a movable and telescopic gun-parallel arm, comprising a frame having an horizontal axis in which the said arm is pivoted by its lower end so as to be capable of rotating with respect to said frame only in the longitudinal plane of symmetry of said frame, a member in the shape of a fork in which said frame is horizontally and rotatably supported so as to be capable of following the gun-parallel arm in its displacements in vertical planes, said member being capable of rotating around a vertical axis passing through the rotation centre of the gun-parallel arm, a dial integral with said fork-shaped member and normally disposed with regard to the horizontal axis of said frame, a finger integral with said frame and adapted to move in front of said dial so that when the horizontal axis of said frame is perpendicular to the sight plane, the said finger indicates the projection upon the sight-plane of the gun parallel arm, i. e. the angle of site of the target, a device for indicating the actual drift angle,

and means for transmitting the said corrections* to the battery.

2. An apparatus for the transmission at a distance of the position in space of a portion of straight line movable around a fixed point, particularly designed to transmit to an anti-aircraft battery of guns or machine-guns the elements of direct and indirect firing obtained by means of an appropriate known corrector provided with a movable and telescopic gun-parallel arm comprising a frame having an horizontal axis in which the said arm is pivoted by its lower end so as to be capable of rotating with respect to said frame only in the longitudinal plane of symmetry of said frame, a member in the shape of a fork in which said frame is horizontally and rotatably supported so as to be capable of following the. gun parallel arm in its displacements in vertical planes, said member being capable of rotating around a vertical axis passing through the rotation centre of the gun-parallel arm, a dial integral with said fork-shaped member and normally disposed with regard tothe horizontal axis of said frame, a finger integral with said frame and adapted to move in front of said dial so that whenthe horizontal axis of said frame is perpenthe projection upon the sight plane of the gunparallel arm, i. e. the angle of site of the target, a dial integral with said frame, a finger mounted in front of said dial, a rod supportedhorizontally' on said frame and bearing the said finger on its one end, a toothed wheel provided on the oppothe gun-parallel arm andv engaging the said toothed wheel, this finger beingadapted to show on the dial the angle of rotation of the gun paral-'" lel arm with respect to'the frame if. ei'; the actual drift angle, and means for transmitting the said corrections to the battery.

3. An apparatus for the transmission at a distance of the position in space of a portion of straight linemovable around a fixed point, particularly designed to transmit to an anti-aircraft battery of guns or machine-gunsthe elements of direct and indirect firing obtained by means of an appropriate known corrector provided with a movable and telescopic gun-parallel arm comprising a frame having a horizontal axis in which the said arm is pivoted by its lower end so as to be capable of rotating with respect to said frame only in the longitudinal plane of symmetry of said frame, a member in the shape of a fork in which said frame is horizontally and rotatably supported so as to be capable of following the gun-parallel arm in its displacements in vertical planes, said member being capable of rotating around a vertical axis passing through the rotation centre of the gun-parallel arm, a dial integral with said fork-shaped member and normally disposed with regard to the horizontal axis of said frame, a finger integral with said frame and adapted to move in front of said dial so that when the horizontal axis of said frame is perpendicular to the sight plane, the said finger indicates the projection upon the sight plane of the gun-parallel arm, i. e.; the angle of site of the target, a dial integral with said frame, a finger mounted in front of said dial, a rod supported horizontally on said frame and bearing the said finger on its one end, a toothed wheel provided on the opposite end of said rod, a toothed sector integral with the gun-parallel arm and engaging the said toothed wheel, this finger being adapted to show on the dial the angle of rotation of the gun-parallel arm with respect to the frame, i. e. the actual drift angle, and means such as a totalizing differential device for transmitting the said corrections to the battery.

4. An apparatus according to claim 3, in which the totalizing differential device for transmitting the said corrections tothe battery is electrically operated.

5. An apparatus for the transmission at a distance'of the position in space of a portion of straight line movable around a fixed point, particularly designed to be mounted on board of a ship and to transmit to an anti-aircraft battery of guns .or machine-guns the elements of direct and indirect firing obtained by means of an appropriate known corrector provided with a movable and telescopic gun-parallel arm comprising a frame having an horizontal axis in which the said .arm is pivoted by its lower end so as to be capable of rotating with respect to said frame only in, the longitudinal plane of symmetry of around a vertical axis passing through the rotation centre of the'gun-parallel arm, a dial integral-with said fork shapedmember and normal- 1y disposedwith regard to thehorizontal, axis of said frame, a finger integral with said frame and adapted to move in front of saiddial so that when.

v k I I V v Y V e V- 0 site end of said rod atoothed'sector integral with the honzo axls of Sam mme perpendlcular to the sight plane the saidfinger indicates the projection upon ,the sight plane of the gun-parallel arm, i. e. the angle. ofsite of the target, a dial integral with saidframe, a finger mounted in front of said dial, a rod supported. horizontally on said. frame and bearing the said finger on its 1 one,end, a,toothed wheel providedon the opposite-end of said rod, a toothedsector integral with the gun-parallel arm and engaging the said toothed wheel, this finger being adapted to show on the dial the angle of rotation of the gun-parallel arm withrespect to the frame, i. e. the actual drift angle, a disc for supporting the forkshaped member, a gyroscopic device for supp0rt- \ing said disc in a constantly horizontal position,

and means for transmitting the said correction to the battery.

6. An apparatus for the transmission at a distance of the position in space of a portion of straight line movable around a fixed point, particularly designed to transmit to an antiaircraft battery of guns or machine-guns the elements of direct and indirect firing obtained by means of an appropriate known corrector provided with a movable and telescopic gun-parallel arm, comprising a pedestal, between said pedestal and the said gun-parallel arm a universal joint constituted by two members, a vertical shaft journalled in the pedestal and carrying the lower member of the joint, a horizontal shaft journalled in said member, another shaft integral with the preceding one and disposed normally to same, the upper member of the joint being rotatably mounted on said second shaft and integral with the lower end of the gun-parallel arm, a dial integral with the lower member of the joint and disposed normally to its horizontal shaft, a finger integral with said shaftand adapted to move in front of said dial so that when the horizontal axis of said frame is perpendicular to the sight plane, the said finger indicates the projection upon the sight-plane of the gun-parallel ,arm, i. e. the angle of site of the target, a device for indicating the actual drift angle, and means for transmitting the said corrections to the battery.

7. An apparatus according to claim 6', wherein the movements of said gun-parallel arm control the movements of the upper member around its two axes of rotation in the case of direct firingr 8. An apparatus according to claim 6, wherein a wheel is provided for effecting the azimuthal displacement of the lower member around its vertical axis of rotation so as to indicate the drift in the case of indirect firing.

9. An apparatus according to claim 1, particularly adapted for marine guns wherein a device is interposed between said fork-shaped member and the base of the apparatus for executing movements which are exactly opposite to the movements of the deck of the ship or other platform upon which the base is mounted.

10. An apparatus according to claim 1, particularly adapted for marine guns wherein means are provided for introducing an additional reference plane which remains horizontal notwithstanding the movements of the base of the apparatus, said means comprising a pair of circular sliding parts arranged at right angles and interposed between said fork-shaped member and the base of the apparatus, and toothed sectors and cooperating worm wheels for operating said parts.

11. An apparatus according to claim l, particularly adapted for marine guns wherein means are provided for introducing an additional reference plane which remains horizontal notwithstanding the movements of the base of the apparatus, said means comprising a pair of circular sliding parts arranged at right angles and interposed between said fork-shaped member and the base of the apparatus, and toothed sectors and cooperating worm wheels for operating said parts, and additional means for maintaining one of said sliding parts constantly parallel to theguide-line of the ship.

YVES PAUL GASTON LE PRIEUR. AUGUSTE LOUIS RICORDEL. 

